The present invention relates to a showcase in which the inside of a display chamber formed in the main body thereof is illuminated with an illumination apparatus.
Conventional showcases of the above-mentioned type include an open showcase as shown in, for example, Patent Document 1. In such an open showcase, cold air is discharged from an outlet formed at the lower edge of an opening in an insulating wall substantially U-shaped in section toward an inlet at the lower edge of the opening, thereby forming a cold air curtain at the opening. Thus, the inside of a display chamber enclosed by the insulating wall is cooled at a predetermined temperature. Further, a plurality of fluorescent lamps are attached to, for example, a canopy located outside the upper edge of the opening, to both side edges of the openings and to the lower surface of the front of a shelf in order to illuminate the inside of the display chamber and the showcase itself (e.g., see Japanese Patent Application Laid-Open No. 5-146346 (Patent Document 1)).
However, in the conventional open showcase, the fluorescent lamps are used as illumination apparatuses, and the fluorescent lamps are provided, for example, at the front of the upper part of the display chamber and in the lower surface of the shelf put up in the display chamber. This is a disadvantage in that heat load is produced in the display chamber due to the illumination with the fluorescent lamps. In general, a fluorescent lamp converts electric energy into visible radiation, infrared radiation and ultraviolet radiation, and emits visible light, so that the fluorescent lamp is used as illumination. Heat loss is produced at this point, which disadvantageously causes the inside of the display chamber to be heated not only by the fluorescent lamp itself but also by the radiant heat of the fluorescent lamp.
Therefore, cooling efficiency decreases in a cooling showcase which cools the inside of a display chamber at a predetermined temperature because this showcase performs a cooling operation considering the heat load resulting from the illumination. This disadvantageously increases running costs. Another disadvantage is that ultraviolet rays falling on commodities displayed in the display chamber have an adverse effect on the commodities. Still another disadvantage is that the fluorescent lamp uses an alternating current and has the problem of flickering, and thus has an adverse effect on the eyes.
Moreover, the fluorescent lamp has to be replaced when a luminance decrease or lighting defect is caused by deterioration over time. This forces a user to replace the fluorescent lamp, which is unfortunately a troublesome work. There is a need for a constant stock of new fluorescent lamps for replacement, and a storage place for the fluorescent lamps needs to be secured. Furthermore, the fluorescent lamp contains mercury, which disadvantageously prevents the used fluorescent lamp from being easily discarded.
Accordingly, LED illumination components equipped with LED elements have recently been employed to replace the fluorescent lamps. In this case, chip-type LED elements are mainly employed to reduce costs. A plurality of LED elements are arrayed and provided under shelves and in a canopy as LED illumination components.
In this case, the illumination apparatus may be composed of a single LED illumination component laterally provided at the front opening of the display chamber. However, in order to reduce manufacturing costs and to improve handleability, the illumination apparatus can be composed of a plurality of LED illumination components.
However, in this case, lead wires drawn from the LED illumination components are removably connected between the LED illumination components by a wiring connector. This wiring connector is disposed along a substrate to which the LED elements are attached, and is hidden together with the LED elements by, for example, a shade.
In this connection, the shade is made of a light-transmitting, colorless and transparent material to ensure light transmitting properties. Thus, the wiring connector is visible to the outside through the shade, which disadvantageously impairs the appearance. Moreover, the wiring connector is disposed in the vicinity of the LED element, so that light radiated from the LED element is blocked by the wiring connector. This disadvantageously prevents the inside of the display chamber from being effectively illuminated.
Furthermore, the LED element is more of a point light source in contrast with the thick fluorescent lamp. It is therefore disadvantageous that if light of the LED element is blocked by, for example, commodities placed on the shelf, the light does not reach farther, so that it is dark in the inner part of the display chamber and the effects of illumination decrease. Therefore, even if an LED illumination component enabling a predetermined intensity of illumination is provided in the canopy, it is unfortunately impossible to effectively illuminate the inside of the display chamber, particularly, the inner upper part of the display chamber.
The present invention has been made to solve the problems of the conventional arts, and is directed to provide a showcase capable of improving the appearance of an illumination apparatus and also capable of improving the effects of illumination by the illumination apparatus.